1. Field of Invention
This invention relates to hand tools and methods therefor and, more particularly, to wrenches and a method therefor.
2. Description of the Prior Art
When a manufacturer decides to make a change from metric sized fittings to British sized fittings or vice versa, a worker is often faced with the task of determining whether a bolt, for example, is a metric or a British sized fitting. After making the determination, the worker must find the correct wrench for the fitting. The time expended in making the determination and for finding the correct wrench substantially increases assembly time for a machine, such as an automobile, where there are a multiplicity of fittings.
It should be understood that the difference between corresponding metric and British sized fittings is small, but significant. In the United States, bolts for a power steering unit of an automobile, for example, must be tightened in accordance with federal guidelines that necessitate the usage of the correct wrench.
In one portion of the prior art, exemplified by U.S. Pat. No. 995,876, a wrench is disclosed with a rotatable jaw head that has a plurality of jaws. When the jaw head is rotated to position a selected jaw for use on a fitting of a work piece, the handle of the wrench maintains the jaw head against rotation. It should be understood that the choice of jaw sizes is on the order of four or five.
Similarly, U.S. Pat. No. 1,168,204 discloses a wrench with two revolvable wrench heads mounted on respective ends of a handle. A wrench head is maintained against rotation by a locking dog connected to the handle. Each of the wrench heads provides a choice of four or five jaw sizes. Because the wrench heads are mounted on the ends of the handle, a person may find that one of the wrench heads provides an obstacle to gripping the handle.
U.S. Pat. No. 216,690 discloses a handle having a ratchet head on one end and three jaws at the other end. The three jaws each have a shoulder that makes one jaw suitable for use on two sizes of fittings.
U.S. Pat. No. 1,404,881 discloses a tappet wrench set that includes a plurality of wrenches, each with an integrally connected wrench head at opposite ends of a handle. The jaws of one of the wrench heads is oriented with its centerline at right angles to the centerline of the handle. However, each wrench of the set has only two jaws.
U.S. Pat. No. 1,808,190 discloses a plurality of wrenches that are constructed for convenient storage.
U.S. Pat. No. 4,574,665 discloses a ratchet type wrench wherein two sets of cusps make it suitable for use on metric and a similarly British sized fitting.
It should be understood that whenever a plurality of tools are used to work with different sized fittings of a work piece, there usually is a loss of time as the worker puts aside one tool and looks for another tool. Heretofore, there has not been a suitable way of minimizing the loss of time without using wrenches that are complex and expensive.